Antenatal and delivery practices and neonatal mortality amongst women with institutional and non-institutional deliveries in rural Zimbabwe: observational data from a cluster randomized trial

Background Despite achieving relatively high rates of antenatal care, institutional delivery, and HIV antiretroviral therapy for women during pregnancy, neonatal mortality has remained stubbornly high in Zimbabwe. Clearer understanding of causal pathways is required to inform effective interventions. Methods This study was a secondary analysis of data from the Sanitation Hygiene Infant Nutrition Efficacy (SHINE) trial, a cluster-randomized community-based trial among pregnant women and their infants, to examine care during institutional and non-institutional deliveries in rural Zimbabwe and associated birth outcomes. Results Among 4423 pregnant women, 529 (11.9%) delivered outside a health institution; hygiene practices were poorer and interventions to minimise neonatal hypothermia less commonly utilised for these deliveries compared to institutional deliveries. Among 3441 infants born in institutions, 592 (17.2%) were preterm (< 37 weeks gestation), while 175/462 (37.9%) infants born outside health institutions were preterm (RR: 2.20 (1.92, 2.53). Similarly, rates of stillbirth [1.2% compared to 3.0% (RR:2.38, 1.36, 4.15)] and neonatal mortality [2.4% compared to 4.8% (RR: 2.01 1.31, 3.10)] were higher among infants born outside institutions. Among mothers delivering at home who reported their reason for having a home delivery, 221/293 (75%) reported that precipitous labor was the primary reason for not having an institutional delivery while 32 (11%), 34 (12%), and 9 (3%), respectively, reported distance to the clinic, financial constraints, and religious/personal preference. Conclusions Preterm birth is common among all infants in rural Zimbabwe, and extremely high among infants born outside health institutions. Our findings indicate that premature onset of labor, rather than maternal choice, may be the reason for many non-institutional deliveries in low-resource settings, initiating a cascade of events resulting in a two-fold higher risk of stillbirth and neonatal mortality amongst children born outside health institutions. Interventions for primary prevention of preterm delivery will be crucial in reducing neonatal mortality in Zimbabwe. Trial registration The trial is registered with ClinicalTrials.gov, number NCT01824940. Supplementary Information The online version contains supplementary material available at 10.1186/s12884-022-05282-x.


Introduction
Globally, neonatal mortality fell by 51% between 1990 and 2017 from 36.6 to 18.0 deaths per 1000 live births and the absolute number of annual neonatal deaths halved from 5 million to 2.5 million [1]. Despite these gains, more than 60 countries are not on track to meet the neonatal mortality (NNM) target of 12/1000 highlighted in the Sustainable Development Goals (SDGs) [1].
Most neonatal deaths occur during delivery [2,3] or in the first 24 hours following birth [4,5]. As such, efforts to reduce neonatal mortality have focused on encouraging and enabling women to deliver in health facilities, in the presence of skilled birth attendants (SBAs) [6,7], which is associated with lower adverse outcomes in both infants and mothers [8][9][10].
Whilst many studies have focused on the reasons why women choose to deliver at home, there has been less discussion of women who intend to deliver in an institution but end up delivering at home when labour occurs unexpectedly early and /or progresses quickly. This situation may be especially relevant for women living in remote rural settings with poor infrastructure and limited transportation. Indeed in studies in Nepal, Kenya, and Tanzania examining reasons for non-institutional deliveries, one-third [11,12] to two-thirds [13] of women reported precipitous or unexpectedly early labour as the primary reason they delivered at home.
In Zimbabwe, neonatal mortality has been a particularly stubborn problem: it increased from 27/1000 to 32/1000 live births between 1990 and 2019, in part reflecting economic hardship and high HIV prevalence [14]. This increase occurred despite high coverage of prevention of mother-to-child transmission (PMTCT) interventions (> 90% in 2018) [15], antenatal care (93% with ≥1 visit and 74% with ≥4 visits), and institutional deliveries (88%) [16]. The Sanitation Hygiene Infant Nutrition Efficacy (SHINE) trial was a cluster-randomized community-based trial conducted in two contiguous rural Zimbabwean districts (Chirumanzu and Shurugwi) which tested the independent and combined effects of improved infant and young child feeding (IYCF) and improved water, sanitation, and hygiene (WASH) on child health outcomes. This secondary data analysis from the SHINE trial provides an opportunity to examine the risk factors, birth practices and infant outcomes among women having institutional or non-institutional deliveries.

Sanitation hygiene infant nutrition efficacy (SHINE) trial
The SHINE trial has been previously described [17] and primary outcomes reported [18][19][20]. In brief, mothers and their infants were randomized to standard of care (SOC); IYCF (small-dose lipid-based nutrient supplement and complementary feeding counselling from 6 months of age); WASH (commencing during pregnancy with pit latrine and 2 hand-washing stations, liquid soap and chlorine, a clean play space, and hygiene counselling); or IYCF + WASH (all interventions). Primary outcomes were infant length and haemoglobin at 18 months, with several secondary outcomes, including child neurodevelopment, infant diarrhoea prevalence, incidence, and severity, and adverse birth outcomes.

Data collection and analysis
From November 22nd, 2012, to March 27th, 2015, Village Health Workers (VHWs) employed by the Ministry of Health and Child Care (MoHCC) conducted prospective pregnancy surveillance by visiting all women aged 15-49 years in the study area to identify those who had missed a menstrual period and offering them a urine pregnancy test. New pregnancies were referred to research nurses who obtained written informed consent and enrolled women into the trial.
Home visits were carried out at baseline (~ 2 weeks after enrolment), at 32 gestational weeks, and at infant ages 1, 3, 6, 12 and 18 months to assess baseline characteristics and trial outcomes. Given the household nature of the WASH intervention, visits were only conducted when the mother was available in the home where she had been recruited, except at the 18-month visit (trial endpoint) when they were visited anywhere in Zimbabwe. Information about the delivery and the infant at birth was collated from the mother's handheld records, the health facility records and by questionnaire at the 1-month postpartum visit or, for mother-infant dyads not available for the 1-month visit, at their first available postpartum visit. The trial provided Tanita BD-590 infant scales (Arlington Heights, IL, USA) to all institutions in the study area and trained health facility staff to use the scales and record infant birth weight on facility and patient-held records. Recumbent infant length was measured to the nearest 0.1 cm using a Seca 417 infantometer (Weigh & Measure LLC., Olney, MD, USA) by a research nurse during home visits at 1 month as an indicator of fetal linear growth. Gestational age at delivery was calculated from the date of the mother's last menstrual period; values which were < 24 weeks or > 42 weeks + 6 days were excluded from analyses. Infants were classified as preterm (gestational age at delivery < 37 weeks), small-for-gestational-age (SGA; birthweight <10th percentile for gestational age using the INTERGROWTH reference [21]), or both preterm and SGA. Mean gestational age at delivery and proportion of infants born preterm (< 37 weeks) were estimated among two populations: first, only among infants with complete and plausible data, defined as those with birthweight-for-gestational age > 0.4th centile and < 99.6th centile using INTERGROWTH references (Estimate 1); and second, including infants in Estimate 1 plus infants whose birth weight was missing (Estimate 2). Infant length at 3 month was converted to Z-scores using the WHO reference [22].
Fetal losses and neonatal deaths were identified and reported to the trial by a research nurse, VHW, or the mother. Details of the event were reported by a research nurse to the study physician who reviewed the reports and classified the event as miscarriage (fetal loss before 28 weeks' gestation), stillbirth (fetal loss after 28 weeks' gestation), or neonatal death (live birth followed by death within the first 28 days) and reported them to the institutional review boards which approved and oversaw the trial (Medical Research Council of Zimbabwe and Johns Hopkins Bloomberg School of Public Health). Women gave written informed consent to participate.

Statistical analysis
Baseline characteristics, care practices, and birth outcomes of women who had institutional compared to noninstitutional deliveries were compared by calculating the mean difference (95% CI) for continuous variables and relative risk (95% CI) for categorical variables. All statistical analyses were performed using STATA version 14 [23]. Selection of care practices was guided by the WHO safe childbirth checklist (ref ).

Results
Five thousand, two hundred eighty pregnant women were enrolled from 211 clusters at a median gestational age of 12 (IQR 9-16) weeks (Supplementary Figure). During the antenatal period, 11 women were excluded, and one woman was added to the analysis to correct for enrolment errors; 139 women withdrew from the trial or were lost to follow-up, 4 died during pregnancy and 249 had a miscarriage. With the addition of 82 fetuses in twin/triplet pregnancies there were a total of 4956 fetuses delivered by 4878 mothers. Of these, place and details of the delivery was known for 4494 fetuses (90.7%) (4423 mothers); 3958 fetuses (88.1%) (3894 mothers) were delivered in an institution and 536 fetuses (11.9%) (529 mothers) were delivered outside a health institution.
Compared to women who delivered in a health institution, women who delivered outside a health institution were older, less likely to be primiparous, more likely to have been depressed during pregnancy, more likely to belong to the Apostolic faith and to have a lower socioeconomic status including fewer years of education, and poorer sanitation and drinking water quality (Table 1). Whilst mothers who had non-institutional deliveries were less likely to have had an HIV test prior to joining SHINE (RR 0.91, 95%CI 0.84-0.97), they were 39% more likely to test HIV-positive during the baseline visit of the trial. History of previous neonatal death, miscarriage, and stillbirth did not significantly vary by place of delivery.
Many conditions and care practices during delivery differed between institutional and non-institutional deliveries (Table 2) [24]. Women who delivered outside a health institution were less likely to have paid for delivery than those who delivered at a health institution. Only a small number (N = 25, 5.1%) of non-institutional deliveries were assisted by a healthcare professional (doctor, nurse, or midwife), compared to almost all (N = 3857, 99.5%) births at health institutions. Instead, non-institutional deliveries were more commonly assisted by VHWs, traditional birth attendants, faith healers, friends, or relatives. Several indicators suggested that fewer hygiene measures were taken during non-institutional births: birthing assistants were less likely to use gloves (RR 0.68, 95%CI 0.64-0.73), sterile blades to cut the cord (RR 0.97, 95%CI 0.93-1.00), or sterile string to tie the cord (RR 0.36, 95%CI 0.32-0.41). Unclean string was used to tie the cord in 22.5% (N = 101) of non-institutional births. Furthermore, infants born outside an institution were less likely to be dried (RR 0.72, 95%CI 0.66-0.79) and placed skin-to-skin with the mother (RR 0.22, 95%CI 0.18-0.28) before delivery of the placenta, which are both important indicators of neonatal hypothermia risk [25,26]. Among 293 women who provided Information on their reason for having had a home delivery, 221 (75%) reported that precipitous labor was the primary reason for not having an institutional delivery while 32 (11%), 34 (12%), and 9 (3%), respectively, reported distance to the clinic, financial constraints, and religious/personal preference.

Discussion
In the SHINE study population, 18.2% of infants were born preterm and 57% of both the neonatal deaths and stillbirths were among infants born prematurely [27]. This preterm birth rate is among the highest in the world. A key insight of the current analysis is that the proportion of infants born preterm was 2.2 (95% CI: 1.92, 2.53) times higher among infants with noninstitutional compared to institutional deliveries (37.9% vs 17.2%). While previous studies have focussed on determinants of non-institutional deliveries which then lead to poorer birth outcomes [28][29][30], our observations imply the reverse: the highly prevalent (and unexpectedly early) preterm labor experienced by SHINE mothers may be the reason many of these mothers delivered outside a health institution. Moreover, we observed many of the same risk factors of non-institutional delivery (e.g., lower socioeconomic status) that have been reported by others. This implies that among the many women in Zimbabwe who experience preterm labor, those who are also poorer, less educated, and more depressed, lack the means to reach a health institution quickly, and so are attended by untrained caregivers in less hygienic conditions. This cascade of events likely contributed to the two-fold higher risk of stillbirth and neonatal mortality among non-institutional deliveries in our study. This offers a potential explanation for the findings of a recent study carried out in Zimbabwe which found that women, burdened by multiple interacting vulnerabilities related to poverty, were most likely to deliver 'on the road' whilst attempting to reach a healthcare institution [31].   In recent years, substantial progress has been made in scaling up interventions for small and sick neonates. These include affordable devices for continuous positive airway pressure for respiratory distress syndrome [32,33], training health workers in neonatal resuscitation [34], surfactant therapy for premature infants [35] and steroid [36] and antibiotic [37] therapy for meconium aspiration and severe infection. While these interventions have made huge contributions to improving neonatal survival, all are hospital-based. Our observation that at least 20% of the preterm births in the SHINE study population occurred outside a health institution, demonstrates that in addition to interventions for enhanced neonatal care, there is an urgent need for interventions that prevent preterm labor. There are now three evidence-based interventions for preventing preterm birth which are low cost and safe during pregnancy. In populations with low dietary calcium intake, antenatal calcium supplementation at doses of ≥1 g per day can reduce preterm birth by 24% according to a recent Cochrane Review [38]. Indeed, since 2016, the World Health Organization has recommended 1.5-2.0 g calcium supplementation throughout pregnancy for women with low dietary calcium primarily for its effect on reducing preeclampsia, although this recommendation has not been widely scaled up. In a recent trial among 12,000 pregnant women in 6 LMICs, daily low-dose (81 mg) aspirin reduced preterm birth by 11% [39] without any excess adverse side effects. Replacing iron-folate with multiple micronutrient supplementation may also modestly reduce the risk of preterm birth, [40] especially when initiated early in pregnancy [41]. Other interventions which might be considered in the future include omega-3-poly-unsaturated fatty acids (shown to reduce preterm birth in most [42,43] but not all [44] trials) and anti-inflammatory drugs (e.g., a trial of cotrimoxazole, which has potent anti-inflammatory effects [45], is underway in Zimbabwe (PACTR202107707978619) and pharmaceutical preparations of specialized proresolving lipid mediators are under development [46,47]).

Conclusion
This study supports the existing literature in describing the sociodemographic profiles of women who have non-institutional deliveries in rural Zimbabwe. These women are often poorer, less well educated, and more likely to have HIV than those women who give birth at a health institution. As would be expected, the standard of care which women receive outside a health institution is inferior to that provided in health institutions, with poorer access to experienced health professionals and sanitation.
Our findings indicate that preterm birth rates are particularly high amongst non-institutional deliveries, suggesting that premature onset of labor, rather than maternal choice, may be the reason for many home deliveries. Interventions for primary prevention of preterm delivery will be crucial in reducing neonatal mortality in Zimbabwe.